Penn & Leighton had phenomenal chemistry. Before their character's even started their thing, Blair & Dan interaction was always great. Even when they were snipping at one another. I always thought Leighton's chemistry with the dude that plays Chuck wasn't there. And for Penn & Blake to be dating outside of the show for the majority of the time & then to have their characters dating? They were so bland & stale. Ugh. Dan & Blair were perfect together & weirdly complimented each other.
Yeah, I mean it's hard to have chemistry with Ed when he was the original Batman Voice OneNote Manpain on The CW. Bob clearly takes after him. I swear the CW has a knack for finding bad actors, but easily the worst three leading ones they've every employed have to be Bob, Ed, and Blake. They all have one emotional note, one voice, and one facial expression. I've watched paint dry that makes me feel more than any of them.
Dan and Blair worked because their banter was so good and the banter was so good because Penn and Leighton had such incredible chemistry. It's a shame to see such potential for character work AND good story thrown away for fanservice.